SESAME - 1995
Afternoon at Kiruna
 
In February of 1995 our first instrument was flown on a scientific balloon launched near Kiruna, Sweden at  ESRANGE, the Swedish rocket facility. The photo above was taken in the early afternoon in late January from the road to the top of a hill where the telemetry and command center are located. The sun doesn't get much higher than this at noon. Driving up this hill too fast is quite an experience; several cars had to be pulled out of snow banks during the week we were there. Kiruna is a wonderful place in January and February if you are interested in studying wintertime Arctic ozone loss. Ours were the first successful in situ measurements of ClO and BrO above 20 km in the perturbed Arctic vortex. The results are discussed in two papers (McKinney et al., 1997, Pierson et al., 1998).
 UCI Halogen Oxide Instrument
In 1994 we began constructing a new instrument for fast response measurements of ClO and BrO using the technique of resonance fluorescence. This work was the next logical step in reducing the size and weight of an instrument that we flew on a balloon over New Mexico in 1991 when I was a postdoc with the  Anderson Group  at Harvard University. This instrument was built with the assistance of my two graduate students (Jim Pierson and Karena McKinney), two postdocs (Roy Dixon and Troy Mazely) and one undergraduate (Jason Low). The gondola was designed and built with the help of Ralph Kolbush, the former head of the UCI Physical Sciences Machine Shop. The resulting instrument, shown here, weighed about 45 kg, including batteries and frame. From this angle, the roots blower (borrowed from Harvard), data acquisition system, power supply, distribution panel, and batteries are clearly visible.
 

Halogen Oxide detector
In this view of the instrument, the gas deck, two resonance fluorescence detection modules, and two additional battery packs are clearly visible. The inlet at the bottom is covered with a sheet of bubble wrap to protect the inside of the instrument from dust. For chemical reasons, the first (lowermost) detector measured ClO, the second, BrO.
This is the building that is used to prepare payloads on the evening before flight. This is one of the examples of the excellent facilities at Esrange.
 
 

KFA Gondola
Our instrument was incorporated into a larger payload developed at KFA, Juelich, and flown by Ulrich Schmidt (now at University of Frankfurt) and his colleagues to measure long-lived tracers. Their work represents the only long-term, "continuous" record of the build up of chlorofluorocarbons in the stratosphere, a result that mirrors the behavior in the troposphere. This photo shows the gondola about an hour before launch, when the temperature was about -28 C. In the left portion of the gondola is the KFA cryosampler, our instrument in on the right, and Jim Margitan's ozone photometer is on the top. Two additional instruments (smaller, so harder to see in the photo) measured particles and solar flux. The all-metal open construction of the gondola and "crush pad" are important for minimizing species that outgas from other types of gondolas.

Early AM Launch
Inflation of the balloon on the morning of February 3, 1995. The main balloon, on the right, is 100,000 m^3, and carried the payload to 27 km. The small auxiliary balloon at the far left is sufficient to hold the ~400 kg payload (including load line and ballast) at neutral bouyancy until the main balloon is released. This scheme eliminates the need for a large crane to hold the payload, making launch easier under adverse conditions.

Our launch on February 3 occured before sunrise, so there are no photos. However, there were a number of other launches of large balloons at ESRANGE during SESAME.  Click here for photos of a daytime launch.
 
 

Communications Dish
After launch, the balloon and payload are tracked continuously by the radars on a nearby hill. This is a photo taken in the afternoon of one of the large communcations dishes. Our balloon was tracked for several hundred miles for three hours as it traveled in the polar jet in a southeast direction from Kiruna. The payload was ultimately cut away onto a parachute over Finland, and it landed between Oulu and Helsinki.